SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '4d4e6adf8c43389bea9f2de72c1eab13f5a2946f9d28ec5b0e8bf1e59a01c067' 
  AND token = 'xVBlkDAX/IA4chuRerZJU9btD2Abd4v8ZE57fhPv+r8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00043

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}